The primary goal is the demonstration of regulatory genes in a eukaryote. The three hemoglobins of the brine shrimp, Artemia salina, are a good system for the assay of regulatory mutations because the hemoglobins are inducible, not essential for life, and the assay if for the amount (not the activity) of the product of structural genes. The three wild type hemoglobins will be characterized by isolating the polypeptides, analyzing the amino acid content, and determination of molecular weight. Variant hemoglobins will be characterized in regard to structure, mode of inheritance, and incidence in wild populations. Classical genetics studies will show if the structural and regulatory loci are linked, etc. In our studies of induction of hemoglobins in individual shrimps, we will also observe the effects of environment (temperature, partial pressure of oxygen or carbon monoxide, nutrition) on mode of reproduction, viability, and concentration in the hemolymph of certain proteins (hemoglobins, biliproteins, and lipoproteins).